Inertial switch device



July 13, 1965 F. R. EDGARTON 3,194,910

iNER'I'IAL SWITCH DEVICE Filed 001:. 4, 1962 7 Sheets-Sheet 1 INVENTOR.

mwmr 19.60602 0 arraewers July 13, 1965 F. R. EDGARTON 3,

INERTIAL SWITCH DEVICE Filed 001;. 4, 1962 '7 Sheets-Sheet 2 INVEN TOR. FAIA A' 8 060: 7'04 July 13, 1965 F. R. EDGARTON 3,194,910

INERTIAL SWITCH DEVICE Filed Oct. 4, 1962 7 Sheets-Sheet 5 Fig-i INVEN TOR. hen/VA e oameram r L n Tree/vars July 13, 1965 F. R. EDGARTON 3,194,910

INERTIAL SWITCH DEVICE Filed Oct. 4, 1962 '7 Sheets-Sheet 4 INVENTOR. F0000? k. 626M670 July 13, 1965 F. R. EDGARTON INERTIAL SWITCH DEVICE 7 Sheets-Sheet 5 Filed 001;. 4, 1962 H a a? Hm. I 7 KW W W M M F F. R. EDGARTON INERTIAL SWITCH DEVICE July 13, 1965 7 Sheets-Sheet 6 Filed Oct. 4, 1962 IN VEN TOR. fXW/VK I. [06/9 704 United States Patent 3,194,910 ENERTIAL SWITH DEVICE Frank R. Edgarton, Inglewood, Calih, assignor to the United States of America as represented by the Secretary of the Air Force Filed Get. 4, 1962, Ser. No. 228,5ti5

16 Claims. (61. Nil-61.45)

- This invention relates to switch devices of the automatic or nonmanual type. More specifically, this invention relates to switches and their actuating mechanism suitable for use on ballistic missiles and other applications encountering the forces of acceleration and deceleration.

For convenience, the present invention will be shown and described as applied to a ballistic air-to-air missile. It must, however, be strictly understood that such use is for purposes of illustration only and is in no way intended to restrict the invention from other equally applicable uses.

Ballistic missiles are extremely potent and dangerous weapons, not only against enemy forces, but also in their care, storage and use by our own forces. All components of such missiles, including the operating and control devices must be designed and built for optimum reliability toprevent accidents and malfunctions.

A ballistic missile, such as fired from friendly aircraft against enemy aircraft, presents several unique and complex control problems. In the first place, such missile must not be armed or made unsafe until the missile has been launched a suilicient distance from the launching aircraft that an explosion would be beyond the lethal range of the aircraft and its operating personnel.

Another control problem of an air-to-air ballistic missile is to provide a means for self-destruction of the missile in those cases where no target is met during a prescribed time of flight. Without such provisions for self-destruction, the missile would explode upon ground impact and could well be as destructive to friendly as to enemy troops and installations.

The above problems resolve themselves into the necessity of providing a means for retaining the missile in a safe or unarmed condition to a predetermined point, of then arming the missile to a condition under which an explosion would occur if a target is met and, finally, if no target is met, to cause self-destruction.

The device of the present invention uses the acceleration and deceleration of the missile in flight as the parameters controlling the transition of the missile from the safe condition. The multipole switch of the present invention maintains the warhead energizing and firing circuits in their open or safe position until such time as the middle is to be armed. The effect of the acceleration of the missile during the period of combusting the propellant is applied in the switch device by means of an inertia weight called the .positive' G-Weight and the effect of the deceleration of the missile in flight after combusting the propellant is applied in the device by means of a second inertia weight called the negative G-weight. The action of the G'weights will be described hereinafter.

The acceleration force of the missile during the period of combustion falls within 'a definitc'and measurable G- range. The positive G-weight is of such mass as to have the proper reaction in this specific G-range in order to achieve thecorrect reaction in the actuating portion of the device. The design of the actuating portion of the device, including the G-weights is such that the composite device is relatively nonsensitive to acceleration falling outside the normal acceleration of the missile.

The necessity for making the device nonsensitive to acceleration forces outside the G-range of the missile is to prevent arming the device because of an accidental dropping or from the eifect of being carried by an airplane which itself has acceleration and deceleration during normal operation.

Likewise, as will be explained hereinafter, the present invention will not arm or unsafe the missile unless a single acceleration burst lasting for a predetermined minimum length of time acts on the positive G-weight. In other words, the device is nonintegrating in that several accelerations within the properG-range but of shorter duration, cannot be made cumulative to arm the missile. This is accomplished by having the device return to the initial safe or zero position after each acceleration of hor duration, in order to re-establish the base zero position from which an acceleration of proper duration must be measured. i

The primary function of the negative G-weight is to compensate for the various flight altitudes from which the ballistic missile may be fired. As previously stated, the missile is not to be armed until it has become launched a suflicient distance from the launching airplane that the airplane would be beyond the lethal range of the missile. This minimum launching distance and time of flight required to achieve such distance is a function of altitude.

The safe minimum distance at which a missile may be exploded is increased as the altitude is increased. As the altitude increase, the mathematical value of the missile drag or deceleration after combustion of the propellant is a decreasing function of the altitude. This drag or deceleration, acting on the negative G-weight, influences the time after launch at which the missile becomes armed. This negative G-weight as used in the present invention is a simple means of making altitude correction without the useof complex and delicate barometric devices. Specific functional operation and method of accomplishing the altitude adjustment by means of the negative G-weight will be described hereinafter.

The various operational mechanical elementsare countor-balanced to make the switch device nonsensitive to extraneous forces other than the action of the positive and negative G-weights. Likewise, as will be hereinafter described, provision is made by a unique dielectric el ment insertable between the contact points of the multipole switch during the safe condition for additional assurance against any premature electrical contact produced by extraneous forces acting'on the switch elements.

The primary object of the invention is to provide an inertial switch device having optimum reliability.

Another object of this invention is to provide an inertial switch device for the control of the warhead energizing, tiring and self-destruct circuits on a ballistic missile.

A further object of this invention is to provide an inertial switch device for the control of electrical circuits on a ballistic missile and in which altitude compensation may be made without the use of barometric devices.

Yet another object of this invention is to provide an inertial switch actuated by the forces of both acceleration and deceleration to produce a composite resultant.

A still further object of the invention is to provide an inertial switch which is nonlntegrating to a series of individually insufficient actuating forces.

Still another object of the invention is to provide an inertial switch having dielectric means between the contact points to prevent premature circuit closure.

Additional objects, advantages and features of the invention reside in the construction, arrangement and combination of parts involved'in the embodiment of the invention as will appear from the following description and accompanying drawings, wherein:

FIG. 1 is a plan view of the inertial switch device in the safe or unarmed position, and having aportion of the power springs broken away for clarity in showing a portion of the multipole switch.

FIGURE 2 is a sectional elevation along the line 2-2 of FIG. 1 showing the negative G-weight in the safe or unarmed position.

FIGURE 3 is a sectional elevation along line 3-3 of FIG. 1 showing the positive G-weight in the safe or unarmed position.

FIG. 4 is a sectional elevation along line 4-4 of FIG. 1 showing the multipole switch with the dielectric safety switch block between the points of the switch.

FIG. 5 is a sectional elevation similar to FIG. 4 showing the dielectric safety switch block retracted and the contact points on the switch in the closed position.

FIG. 6 is an end elevation along line 6-6 of FIG. 5 showing the spring end of the multipole switch rotated 90 and showing the general construction of the switch.

FIG. 9 showing construction details of the counterweight.

FIG. 12 is a side elevation along line 12-12 of FIG. 9 showing construction details of the rate cam.

FIG. 13 is a sectional elevation along line 13-13 of FIG. 12.

FIG. 14 is a side elevation along line 14-14 of FIG. 13.

FIG. 15 is 'a side elevation along line 15-15 of FIG. 1.

FIG. 16 is a sectional elevation along line 15-16 of FIG. 15 showing the adjustable cam stop for limiting the rotation of the camshaft assembly in the unsafe or armed position.

FIG. 17 is a perspective of the safety switch block showing the dielectric or insulating material bonded in lace. P FIG. 18 is a schematic end view of the camshaft assembly in the safe or unarmed position.

FIG. 19 is a schematic end view of the camshaft assembly on the dead center position.

FIG. 20 is a schematic end view of the camshaft assembly in the unsafe or armed position.

Referring in particular to FIG. 1, the inertial switch device referred to generally as switch has for its more essential elements a multipole electrical switch 29,

a camshaft assembly 26 directly coupled to an untuned .escapement 27 operable in either direction of rotation for regulating or damping the rate of camshaft rotation in both directions, a power spring 28 cantileverly mounted on the frame for engaging and motivating the camshaft assembly in addition to closing the contact points on the multipole switch 29, the positive G-weight 3% which during the period of missile acceleration moves the camshaft assembly from the safe to the commit position, the negative G-weight 31 which during the initial period of missile deceleration controls the rate at which the untuned escapement permits the camshaft assembly to rotate into the terminal unsafe or armed position, and a safety switch block 32 operated by the camshaft assembly.

The camshaft assembly 26 is journaled in a manner well known to the art by precision ball bearings at each end, which hearings in turn are supported by the frame of the switch. The positive G-weight and the negative G-weight 31 are positioned on shaft supported bearings as shown on FIG. 2 and FIG. 3. The specific configuration of the arrangements will be described hereinafter.

The movement of both G-weights is normal to the axis of the camshaft assembly 26 and the movement of the G-weights is such as to either produce rotation or to impede rotation of the camshaft assembly.

The untuned escapement 27 is of a well-known conventional type. An untuned escapement is unlike a tuned escapement such as used in a watch. A tuned escapement is designed for a constant beat within reasonable limits regardless of the spring pressure or other driving force causing the escapement to operate. The beat of an untuned escapement, however, within reasonable limits, will vary as a function of the pressure applied against the escapement. This variable beat feature, as will be explained hereinafter, is very important to the proper functioning of the switch.

The camshaft assembly 26 comprises two cams rotating about a common axis. The major cam referred to as the arming cam 26a is in engagement with the power spring 28 and the positive Gweight. The minor cam, referred to as the rate cam 25b will engage the negative G-weight 31. The arming cam 26a and the rate cam 26b are at an angular displacement to each other on the common center of rotation.

The cyclic operation of switch 25 may be explained by reference to the schematic figures, FIG. 18, FIG. 19 and FIG. 20. Referring specifically to FIG. 19, the arming cam 26a and the rate cam 26b are shown to have a common center of rotation. For convenience, the two cams are shown displaced apart, although the displacement on the actual switch is somewhat less as shown on FIG. 12, FIG. 13 and FIG. 14. The displacement has no bearing on the invention and may be selected to fit the application.

FIG. 18 shows in schematic the relative positions of the arming and rate cams when the switch is in its initial safe or unarmed position. The actual position is shown by the solid lines and the dead center position as indicated on FIG. 19 is superimposed by dotted lines. The power spring 28 acts on the left side of the dead center axis and resists rotation of the cams in a clockwise direction. As shown in schematic form, rotation of the cams can be produced only by force applied from the movement of the positive G-weight acting against the arming cam.

As has been previously stated, the switch 25 is nonintegrating and will return to its initial or base position unless the force applied by the positive G-weight is great enough and is of long enough duration to rotate the camshaft assembly beyond the dead center or commit position. It may be seen from FIG. 18 that as the cams rotate clockwise, the point of tangency between the power spring 28 and the arming cam 26a will approach the dead center axis. Further, that so long as the point of tangency is to the left of the dead center axis, the biasing force from the power spring will return the cams to the initial position at any time applied force from the positive G-weight decays. As previously noted, the untuned escapement is directly connected to the camshaft assembly and operates in either direction. It is noted that the escape'ment operates in one direction when the camshaft assembly is rotated clockwise and in the opposite direction when the camshaft assembly is rotated counterclockwise. It is further noted, as shown on FIG. 18, that the negative G-weight does not come into operable contact with the camshaft assembly between the initial or safe position and the dead center position shown on FIG. 19.

FIG. 20 shows in schematic the relative positions of the arming and rate cams when the switch is in the terminal armed or unsafe position. The actual position is shown by the solid lines and the dead center position is superimposed by dotted lines. As the force applied by the positive G-weight, acting from the initial position of FIG. 18, rotates the cams beyond the dead center position shown on FIG. 19, the point of tangency between the power spring 28 and the arming cam 26b shifts from the left to the right side of the dead center axis and the biasing force will continue to rotate the cams to the terminal unsafe or armed position. The commit position may be said to be that point of the cyclic operation where the power spring 28 can no longer return the camshaft assembly to the initial position but will only advance the camshaft assembly to the terminal position.

It may be broadly stated that during the period of acceleration when the missile is being driven forward by the missile propellant, an acceleration is reached of suificient intensity and duration to permit the positive G-weight to apply the necessary force as shown on FIG. 13 to rotate the camshaft assembly to or slightly beyond the dead center position shown on FIG. 19. The untuned escapement 27 damps the movement of the positive G-weight to establish a time base required to move the camshaft from the initial to the dead center position.

It may be further broadly stated that by the time the camshaft assembly has reached the dead center position or shortly thereafter, the missile propellant will have been expended and the acceleration of the missile will change from positive to negative. The numerical value of the negative acceleration or deceleration will, as has been previously stated, be a function of the altitude.

As has been previously stated, the safe distance at which an air-to-air missile may be detonated after launchingis likewise a function of the altitude. Unlike previous delicate barometric altitude compensating devices, the present invention substitutes a simple negative G-weight 31, operable by the altitude variable negative acceleration, as the means for determining the minimum distance after launch at which the warhead is armed for detonation.

Again referring to FIG. 20, after the positive G-weight 30 has rotated the camshaft assembly beyond the dead center position of FIG. 19, the reserve energy of power spring 28, acting on the right side of the dead center position, will continue to rotate the camshaft to the terminal armed position shown. Barring friction, the elapsed time between the dead center position and the terminal position would vary with the reserve power of the spring and the damping effect inherent in the design of the escape mechanism. In any event, the elapsed time would be uniform without regard to altitude. The damping effect of the escapement on the cam rotation establishes a minimum time base for rotating the camshaft from the dead center to the terminal position.

Stated in simple terms, the negative G-weight is the means for increasing the elapsed time it would otherwise require for the camshaft assembly to rotate from the position of FIG. 19 to the position of FIG. 20. This, as will be explained, is done variably with the altitude of the missile.

After the missile ceases to accelerate, any applied force from the positive G-weight decays, and the G-weight 1 becomes inoperative. This is illustrated on FIG. 20 by not showing the arrow of the force from the positive G- weight as being applied beyond the dead center position. In similar manner on FIG. 18 and FIG. 19, any action of the negative G-weight does not become operative before the camshaft assembly crosses the dead center axis shown on FIG. 19.

If the negative G-Weight were in a locked position as shown on FIG. 19, the camshaft assembly could not rotate beyond such position. In order for the camshaft assembly to make further rotation, the negative G-weight must move to the left. If the negative G-weight moves at a rate slower than the otherwise normal displacement rate of the rate cam, the escapement will be impeded to increase the time required for the camshaft assembly to rotate to the terminal position. As the missile decelerates, the negative G biases the negative G-weight in the direction of the missile flight. Such movement is resisted by spring means to be hereinafter described. As the deceleration forces increase, the negative G-weight moves farther to the left with a like increase in the tension of the spring resisting such movement. It is noted that the rate at which the negative G-weight moves to the left influences the time required for the camshaft as- 6 negative G-weight moves at a slower rate to thus increase the elapsed time required for the camshaft assembly to assume the terminal position.

The inertial switch device of the subiect invention is used as a portion of a safety, arming and self-destruct device, the various components of which are mounted to two bacloto-back frame halves as shown on FIG. 2, for example. Only so much of the complete device as is necessary to explain the present invention is shown mounted to upper frame half 33a. The lower frame half 33.; which is shown fragmentary, supports components not necessary to the present invention and which for that reason are omitted from the drawings. The entire safety, arming and self-destruct device is mounted in 2. hermetically sealed container such as shown on the inventors co-pending application Serial No. 196,836, Hermetically Sealed Container, filed May 22, 1962, now Patent No. 3,174,620.

Referring to FIG. 4, FIG. 5 and FIG. 6, the multipole switch 25 comprises a plurality of individual pole switches 29a bonded together on rods 34 as best shown on FIG. 6. The protruding ends of rods 34 engage holes in upper frame half 33a and hold the multiple switch in place. The switch used may consist of one or more individual switches 2% the precise number used depending upon the required number of circuits to be controlled.

Each individual pole switch 2% has a contact strip 35 and a 'U-shaped heel strip so embedded in a plastic body as shown on FIG. 5. The end of the heel strip extending through the plastic body terminates in a point forming a pivotal anchor on which contact leaf 37 is located as best shown on BIG. 1 and FIG. 5. Contact strip $55 and contact leaf 3? form the contact points of the switch. The forward end of contact leaf 37 is slotted as best shown on FIG. 1. A headed guide pin 38, having the shank imbedded in the plastic body, passes through the slot of the contact leaf 37 to laterally guide the contact leaf 37 as best shown on FIG. 1, and also to limit the upper movement of the contact leaf as shown on FIG. 4. A tension spring 39 between the heel of the contact leaf 3! and the heel of the U-shaped heel strip 36 biases the contact leaf 3? to its normally open position against the bottom of the head on guide pin 38 as best shown on FIG. 4. Suitable electrical leads 46a and 4% may be joined to contact strip 35 and heel strip 36 as shown.

Threaded through the power spring 28 are a plurality of hex socket head screws 41 locked into adjusted position by lock nuts 42. The number of screws ll used corresponds to the number of individual pole switches 29a which makes up the multipole switch 29. Threadably joined to the end of each screw 41 is an insulating blind sleeve 43 which is in actuating contact with the contact leaf 37.

FIGQZO illustrates the vertical displacement of the power spring 28 when the camshaft assembly 25 rotates from the dead center position to the terminal arming position. This vertical displacement of the power spring moves the contact leaf 3'7 from the open position shown on FIG. 4 to the closed position shown on E16. 5.

The safety switch block 32. shown on FIG. 1, FIG. 4, FIG. 5 and FIG. 17 is pivotally joined to the upper frame half 33a by means of two pins 44 as best shown on FIG. 1. Joined to the lower portion of the safety switch block is a counterweight 45 as best shown on FIG. 4 and FIG. 5. The upper end of the safety switch block terminates in a rake-like structure having blade ends 45 each of which is insertable between the end of contact strip 35 and the adjacent portion of contact leaf 3"? on one of the individual pole switches 29a. A dielectric material comprising a plastic insulating pocket 46 is bonded to each of the blade ends it is noted that because of the plastic insulating pockets, when the safety switch block is positioned as shown on FIG. 4, the switch is eifectively blocked from making premature electrical contact under any conditions other than the mechanically controlled condition when the camshaft assembly 26 is positioned to withdraw the safety switch block to the position shown on FIG. 5.

Rotatably mounted on the arming cam portion 26a of the camshaft assembly is a grooved sleeve 47. As best shown on F1. 4 and PEG. 5, a connecting link or coupling 48 having a forked upper end is snapped in place on grooved sleeve 47, and is pivotally joined to the safety switch block 32 by pin 49. The configuration and operation of the various mechanical elements is such that the safety switch block 32 will remain disposed between the contact strip 35 and the contact 37 during the major portion of the cyclic operation of the switch; being withdrawn or retracted as the camshaft assembly approaches the terminal position, thus permitting contact to be made by action of the power spring 28.

Referring to FIG. 9, PEG. l and FlG. 11, camshaft i) has two small diameter ends and 5th) which are coaxial and form the center of rotation of the camshaft assembly 26. Tangent to the small diameter end 580, as best shown on FIG. 10, and to be eccentric to the center of rotation, is the major portion 559; of the camshaft. The portion 5490 forms the arming cam portion Zea of the camshaft assembly. Integral with the camshaft and concentric with the small diameter ends Silo and 56b is gear 51 which engages the untuned escapement 27. The gear is pierced with a hole 52 as shown on FIG. 10. Adjacent to and concentric with small diameter end 5912 is enlarged diameter sea which axially locates the carnshaft dd against the end support bearing.

Rotatabiy supported by the major portion 590 of the camshaft are the following elements in the order shown on FIG. 9: Counterweight 53 having a lug engaging hole 52 of gear 51, a plurality of precision ball bearings 55 corresponding to the number of fingers 28a on the power spring 28, a plurality of plain spacers 56, the grooved spacer 4-7 previously described, the elongated spacer 57, precision bearing 53 which is operable with the positive G-weight in a manner to be hereinafter described, and a portion of the rate cam 59 operable with the negative G-weight.

Referring to FIG. 12, FIG. 13 and FIG. 14, the rate cam 59 is bored through by bore dd to receive small diameter end 545a of camshaft One end of the rate cam has an eccentric boss 61 which contains a counterbore 62 tangent to bore dd and of a diameter to receive the major portion 50c of camshaft 5d. The opposite end of the rate cam 52 also has an eccentric boss 63 at an angle to boss 61 as indicated by line 13-13 on FIG. 12 and of such diameter that the periphery of boss 63 will be tangent to bore 66. It is noted that rate cam 5? has a center of rotation through bore 6t), an eccentric bore 62 on one end and an eccentric boss 63 on the opposite end which is angularly displaced from eccentric bore er. The construction of the rate cam 59 provides two independent eccentrics on a common axis of rotation.

The rate cam 59 is further provided with a counterbaiancing flange 64 having a first edge 65 used as a stop for controlling the initial or safe position of the camshaft assembly 26. Referring to FIG. 2, the initial position of the camshaft assembly is established by means of adjusting screw 66 and firmly locked by lock nut 67.

The counterbalancing flange on rate cam 59 contains a second edge 68 for controlling the terminal position of the camshaft assembly in a manner to be hereinafter described.

Again referring to FIG. 9, after the rate cam 5% is in place on camshaft 59, the precision bearing 69, which is operable with the negative G-weight is put in place. Bearing 69 abuts shoulder 5% on rate cam 59 where it is held in place by ring 79. Ring 70 has a lug 7% which bears against the inner race of the support bearing contained within bearing shell 7?. which is of conventional design and may be joined to the frame by any of several '8 well-known methods. The axial clearance of the camshaft assembly may be adjusted with shims between hearing 69 and ring 7%, or by other well-l nown means which for simplicity have not been shown.

Referring to FZG. l5, bolt 72 passing through portions of upper frame half 33a supports a first precision bearing '73 operable with the positive G-weight, a cam sleeve 74, a second precision bearing '75 operable with the negative G-weight, and a plain spacer sleeve 76. The bolt is held in place by nut 77. As best shown on FIG. 16, cam sleeve 74- has a cam lobe '78 as shown.

As previously stated, the rate cam 5 has a second edge 63 used in determining the terminal position of the camshaft assembly 26. As the camshaft assembly rotates to the terminal or arming position, edge as on rate cam 5? engages the cam lobe 73 of cam sleeve 74. The exact terminal position is established by loosening nut 77, rotating cam sleeve 74 and retightening nut 77.

Referring to FIG. 3 which shows the positive G-weight in the safe position and to FIG. 7 which shows the same weight in the armed position, the positive G-weight Si is an Sshaped structure slidably supported on precision bearings 79. Bearings 7 9 are also used to support the negative G-weight 31 in like manner as shown on FIG. 2. The bearings 79 are supported on bolts 8f passing through p01"- tions of upper frame half 33a. Suitable sleeves Sla and 81b, as shown on FIG. 8, are used in connection with bearings 79 in a manner as sleeves 74 and 76 are used as hearing spacers on FIG. 15. Both the positive and negative G-weights are laterally restrained on the bearings 79 by shoulders in the manner depicted on FIG. 7 and FIG. 8.

Yoked leaf spring 8-2 is pivotally joined to the positive G-weight 3ft by means of pin 33. The free end of yoked leaf spring 82, which is bowed in the general area indicated as 82a on FIG. 7, engages bearing 73 which is supported by the frame. Adjusting screw 54a, which threadably engages the positive G-weight applies pressure to the heel of the yoked spring 82 causing the spring to engage bearing 73 with a degree of loading and also to cause the G-weight to engage the bottom of upper bearing 79 and the top of'lower bearing 79. The adjustment of the spring is locked in place by lock nut 84b. Because of the bow in spring 82, the spring tension is greatest when the tip of the spring engages the bearing 79 and diminishes as the point of tangency moves rearward on the spring. For this reason, the spring biases the G-weight toward the camshaft assembly 26.

Joined to the yoke leaf spring 32 as shown on FIG. 3 and FIG. 7 is rewind cage 35. The rewind cage, in addition to forming the direct link between the positive G- weight and the camshaft assembly, is used in connection with the rewind mechanism mounted on lower frame half 3%. The rewind mechanism (not shown) engages lug $5a' of the rewind cage 35. The rewind cage essentially comprises a fixed half 85a joined to the leaf spring 82 and a movable half $55) pivotally joined to the fixed half by means of pin 850. A light spring 852 biases the movable half to the position shown on FIG. 3. The action of the rewind mechanism, acting through lug $5M, moves the camshaft from the armed position of FIG. 7 to the safe position of FIG. 3. The rewind mechanism is used in connection with the periodic cycling and test procedure of the safety and arming device within its hermetically sealed container. Lug 85d in addition to engaging the rewind mechanism, also provides the stop, as shown on HS. 7, for limiting the movement of the positive G-weight during negative acceleration.

Referring to FIG. 2, yoked leaf spring 86 is pivotally joined to the negative G-weight by means of pin 87. The front end of the leaf spring is provided with a cam surface Sda which engages bearing supported by the frame.

An adjusting screw 88a which threadably engages the negative G-weight 31 applies pressure to the heel as!) of spring 86 causing the spring to engage bearing 75 with a degree of loading. The position of the adjustis held in place by loci; nut 3312.

if desired, the cam surface 86a of spring S6 may be provided with a groove to aid in laterally aligning the spring on bearing 75. Because of the configuration of the cam surface engaging the bearing 75, it is noted that the deflection of the spring is greatest when the tip is tangent to the bearing and that the deflection diminishes as the spring approaches the position shown on PKG. 2. This configuration resultsin a spring biasing the negative G- weight toward the camshaft assembly Joined to the lower face of spring 8% is engagement strip 59 in axial alignment with bearing 69 on rate cam fill. The position of the engagement strip 89 in relation to the bearing 69 is such that no engagement can be made before the cams'iiaft assembly goes slightly beyond the dead center or commit position. This adjustment is made by means of adjusting screw 9dr: vhich threadably engages lug tide on spring 226 and bears against bearing 79 as shown. The travel of the negative (B -weight is limited by adjusting screw hi, the head of which contacts the upper frame half 35a.

The entire mechanism, as described above, is suitably counterbalanced to avoid any influencing forces other than those applied by the power spring 28 and the two G-Weights It is to he understood that the embodiment of the present invention as shown and described is to be regarded as illustrative only and that the invention is susceptible to variations, modifications and changes within the scope of the appended claims.

I claim:

it. A switch device comprising: a frame, a camshaft journaled in said frame, biasing means engaging with and biasing the rotation of said camshaft to an initial g screw Elbe position on one side of the dead center position of engagement and to a terminal position on the other side of the dead center position of engagement, means rotating said camshaft from the initial position to at least slightly beyond the dead center position of engagement with said biasing means, means regulating the rate of rotation of said camshaft, means impeding said regulating means to increase the elapsed time required for said camshaft to rotate from the dead center to the terminal position, and a switch actuatable by the rotation of said camshaft.

2. A switch device comprising: a frame, a camshaft journaled in said frame, biasing means engaging with and biasing the rotation of said camshaft to an initial position on one side of the dead center position of engagement and to a terminal position on the other side of the dead center position of engagement, means rotating said camshaft from the initial position to at least slightly beyond the dead center position of engagement with said biasing means, an untuned escapement damping the rate of rotation of said camshaft to establish a time base rc quired for said camshaft to rotate from the dead center to the terminal position, means impeding said untuned cscapement to increase the elapsed time requirement for said camshaft to rotate from the dead center to the terminal position, said impeding means movably engaging with and resisting the rotation of said camshaft, and a switch actuatable by the rotation of said camshaft. i

3. A switch device comprising: a frame, a camshaft journalcd in said frame, a power spring mounted on said frame and engaging with said camshaft for motivating the rotation of said camshaft to an initial position on one side of the dead center position of engagement and to a terminal position on the other side of the dead center position of engagement, means rotating said camshaft from the initial position to at least slightly beyond the dead center position of engagement with said power spring, an untuned cscapement coupled to said camshaft for damping the rate of rotation of said camshaft to establish a time base required for said camshaft to rotate from the dead center to the terminal position,

10 means impeding said untuned escapemcnt to increase the elapsed time required for said camshaft to rotate from the dead center to the terminal position, said impeding means movably engaging with and resisting the rotation of said camshaft, and a switch actuatable by the rotation of said camshaft.

A switch device comprising: a frame, a camshaft journaled in said frame, a power spring cantileverly mounted to said frame for engaging with and motivating the rotation of said camshaft to an initial position on one side of the dead center position of engagement and to a terminal positionon the other side of the dead center position of engagement, means rotating said camshaft from the initial position to at least slightly beyond the dead center position of engagement with the said power spring, an untuned escapement coupled to said camshaft for damping the rate of rotation of said camshaft to establish a time base required for said camshaft to rotate from the dead center to the terminal position, means impedin said untuned escapement to increase the elapsed time required for said camshaft to rotate from the dead center to the terminal position, said impeding means movably engaging with and resisting the rotation of said camshaft, and a normally open electrical switch mounted on said frame in spaced relationship to said power spring, the contact points of said switch being closed by said powor spring as said camshaft approaches the terminal position.

5'. A switch device comprising: a frame, a camshaft assembly journaled in said frame, said camshaft assembly comprising an arming cam and a rate cam in angularly displaced relationship on a common axis of rotation, at power spring cantileverly mounted to said frame for engaging with the arming cam and motivating the rotation of said camshaft assembly to an initial position on one side of the dead center position of engagement and to a terminal position on the other side of the dead center position of engagement, means rotating said camshaft assembly from the initial position to at least slightly beyond the dead center position of engagement between the said power spring and arming cam on said camshaft assembly,

an untuned escapement coupled to said camshaft assembly for damping the rate of rotation of said camshaft assembly to establish a time base required for said camshaft assembly to rotate from the dead center engagement position between the power spring and thearming cam to the terminal portion of the camshaft assembly, means impeding said untuned escapcment to increase the elapsed time required for said camshaft assembly to rotate from the dead center to the terminal position, said impeding means movabiy engaging with the rate cam on said camshaft assembly for resisting the rotation of said camshaft assembly, and a normally open electrical switch mounted on said frame in spaced relationship to said power spring, the contact points of said switch being closed by said power, spring as the camshaft assembly approaches the terminal position.

base required for said camshaft to rotate from the dead center to the terminal position, impeding means mo /ably joined to said frame and engaging said camshaft for increasing the minimum time base established by said timing means, and a normally open electrical switch mounted on said frame in spaced relationship to said power spring,

the contact points of said switch being closed by said power spring as said camshaft'approachcs the terminal position.

7. An inertial switch device comprising: a frame, an electrical switch mounted on said frame, said switch having normally open exposed contact points, a safety switch block having one end covered with a dielectric and having the opposite end pivotally joined to said frame in such spaced relationship to the contact points of said switch as will permit the dielectric covered end to pivotally enter between the open contact points of said switch, operating means joined to said frame in spaced relationship to said switch for closing the contacts points on said switch and pivotally moving said switch block, and coupling means operably joining said operating means and said switch block, said operating means having an initial position during which said switch block is between the open contact points of said switch and a terminal position for pivotally withdrawing said switch block and closing the contact points of said switch, said operating means being inertially activated.

8. An inertial switch device operable in an accelerating environment comprising: a frame, a switch mounted on said frame, operating means joined to said frame for operating said switch, said operating means having an initial and a terminal position, acceleration sensitive means opera'bly initiating the movement of said operating means from the initial to the terminal position, said acceleration sensitive means being operable in a G-range of predetermined intensity, and damping means coupled to said operating means for establishing the time required for said operating means to move from the initial to the terminal position.

9'. An inertial switch device operable in an acceleration-deceleration environment comprising: a frame, a

switch mounted on said frame, operating means joined to said frame for operating said switch, said operating means having an initial and a terminal position, acceleration sensitive means operably initiating the movement of said operating means from the initial to the terminal position, said acceleration sensitive means being operable in a G- range of predetermined intensity for a predetermined minimum period of time to commit the movement of said operating means to the terminal position, and deceleration sensitive means increasing the time required for said operating means to move from the commit to the erminal position.

10. An inertial switch device operable in an acceleration-deceleration environment comprising: a frame, a switch mounted on said frame, operating means joined to said frame for operating said switch, said operating means having an initial, a terminal and an intermediate commit position, acceleration sensitive means operably initiating the movement of said operating means from the initial to at least slightly beyond the intermediate commit position, said acceleration sensitive means being operable in a G-range of predetermined intensity for a predetermined minimum period of time to commit the movement of said operating means to the terminal position, said operating means being non-integrating to return to the initial position from any movement produced by a single pulse of said acceleration sensitive means not advancing said operating means to at least the intermediate commit position, and deceleration sensitive means increasing the time required for said operating means to move from the commit to the terminal position.

11. An inertial switch device for controlling the electrical circuits on a ballastic missile and operable in an acceleration-deceleration environment comprisin a frame, an electrical switch mounted on said frame, operating means for operating said switch, said operating means comprising a camshaft assembly journaled in said frame and a power spring cantileverly mounted to said frame and engaging said camshaft assembly; said camshaft assembly comprising an arming cam and a rate cam in angularly displaced relationship on a common axis of rotation, said power spring engaging with the arming cam and motivating the rotation of said camshaft assem bly to an initial position on one side of the dead center commit position of engagement and to a terminal position on the other side of the dead center commit position of engagement with the arming cam, a positive G- weight movably mounted on said frame and bearing against the arming cam for rotatin said camshaft assembly from the initial position to at least slightly beyond the dead center commit position of engagement with said power spring, said positive G-weig-h-t being movably activated when the G-range of acceleration reaches a predetermined intensity, said operating means being nonintegrating to return to the initial position from any movement produced by a single pulse of said positive G- weight not advancing said camshaft assembly to at least the intermediate dead center commit position, damping means coupled to said operating means for establishing the time base required for said camshaft assembly to move from the initial to the terminal position, said damping means being an untuned escapement operable in either direction of camshaft rotation; and a negative G- weight assembly comprising a negative G-weight movably mounted on said frame and bearin against the rate cam of said camshaft assembly for impeding the rotation of said haft assembly from th dead center commit to the terminal position and a spring biasing means biasing said negative G-Weight toward said rate cam, said negative G-weight being movably activated from said rate cam against the resistance of said spring biasing means by the force of deceleration.

12,. An inertial switch device for controlling the electrical circuits on a ballistic missile and operable in an acceleranon-deceleration environment comprising: a frame, an electrical switch mounted on said frame, movable dielectric means between the contact points of said switch when in the open position, operating means coupled to said dielectric means for synchronously withdrawing said dielectric means from between the contact points and closing the contact points of said switch, said operating means comprising a camshaft assembly journaled in said frame and a power spring cantileverly mounted to said frame and engaging said camshaft assembly; said camshaft assembly comprising an arming cam and a rate cam in angularly displaced relationship on a common axis of rotation, said power spring engaging with the arming cam and motivating the rotation of said camshaft assembly to an initial position on one side of the dead center commit position of engagement at which the contact points on said switch are open with the said dielectric means between the points and to a terminal position on the other side of the dead center commit position of engagement with the arming cam at which the said dielectric means are Withdrawn and the contact points on said switch are closed, a positive G-weight movably mounted on said frame and bearing against the arming cam for rotating said camshaft assembly from the initial position to at least slightly beyond the dead center commit position of engagement with said power spring, said positive G-weight being movably activated when the G-range of acceleration reaches a predetermined intensity, said operating means being noninte rating to return to the initial position from any movement produced by a single pulse of said positive G-weight not advancing said camshaft assembly to at least the intermediate dead center commit position, damping means coupled to said operating means for establishment a time base required for said camshaft assembly to move from the initial to the terminal position, said damping means being an untuned escapernent operable in either direction of camshaft rotation; and a negative G-weight assembly comprising a negative G-weight movably mounted on said frame and bearing against the rate cam of said camshaft assembly for impeding the rotation of said camshaft assembly from the dead center commit to the terminal position and a spring biasing means biasing said negative G-weight toward said rate cam, said negative G-weight being movably activated from said rate cam against the resistance of said spring bias-ing means by the 'force of deceleration.

13. An inertial switch device for controlling the electrical circuits on a ballistic missile and operable in an acceleration-deceleration environment comprising: a frame, an electrical switch having exposed contact points mounted on said frame, dielectric means movably joined to said frame in spaced relationship to the contact points of said switch, operating means joined to said frame, a coupling operably joining said dielectric means and said operating means, said operating means having an initial position for opening the contact points on said switch and moving said dielectric means between the open contact points and a terminal position for retracting said dielectric means and closing the contact points of said switch, said operating means comprising a camshaft assembly journaled in said frame and a power spring cantileverly mounted to said frame and engaging said camshaft assembly; said camshaft assembly comprising an arming cam and a rate cam in angularly displaced relationship on a common axis of rotation, said power spring engaging with the arming cam and motivating the rotation of said cam shaft assembly to the initial position on one side of the dead center commit position of engagement and to the terminal position on the other side of the dead center commit position of engagement with the arming cam, a positive G-weight movably mounted on said frame and bearing against the arming cam for rotating said camshaft assembly from the initial position to at least slightly beyond the dead center commit position of engagement with said power spring, said positive G- weight being movably activated when the G-range of acceleration reaches a predetermined intensity, said operating means being nonintegrating to return to the initial position from any movement produced by a single pulse of said positive G-weight not advancing said camshaft assembly to at least the intermediate dead center commit position, damping means coupled to said operating means for establishing a time base required for said camshaft assembly to move from the initial to the terminal position, said damping means being an untuned escapement operable in either direction of camshaft rotation; and a negative G-weight assembly comprising a negative G-weight movably mounted on said frame and bearing against the rate cam of said camshaft assembly for impeding the rotation of said camshaft assembly from the dead center commit to the terminal position and a spring biasing means biasing said negative G-weight toward said rate cam; said negative G-Weight being movably activated from saidrate cam against the resistance of'said spring biasing means by the force of deceleration.

M. An inertial switch device for controlling the electrical circuits on a ballistic missile and operable in in acceleration-deceleration environment comprising: a frame, an electrical switch having exposed contact points mounted on said frame, a safety switch block having one end covered with a dielectric and having the opposite end pivotaily joined to said frame in such spaced relationship to the contact points of said switch as will permit the dielectric covered end to pivotally enter between the open contact points of said switch, operating means joined to said frame, a coupling operably joining said switch block and said operating means, said operating means having an initial position for opening the contact points on said switch and pivotally moving the dielectric covered end of said switch block between the open contact points and a terminal position for pivotally retracting the said switch block and closing the contact points of said switch, said operating means comprising a camshaft assembly journaled in said frame and a power spring cantileverly mounted to said frame and engaging said camshaft assembly; said camshaft assembly comprising an arming cam and a rate cam in angularly displaced relationship on a common axis of rotation, said power spring engaging with the arming cam and motivating the rotation of said camshaft assembly to the initial positionon one side of the dead center commit position of engagement and to the terminal position .on the other side of the dead center commit position of engagement with the arming cam, a positive G-Weight movably mounted on said frame and bearing against the arming camfor rotating said camshaft assembly from the initial position to at least slightly beyond the dead center commit position of engagement with said power spring, said positive G-weight being movably activated when the G-range of acceleration reaches a predetermined intensity, said operating means being nonintegrating to return to the initial position from any movement produced by a single pulse of said positive G- Weight not advancing said camshaft assembly to at least the intermediate dead center commit position, damping means coupled to said operating means for establishing a time base required for said camshaft assembly to move from the initial to the terminal position, said damping means being an untuned escapement operable in either direction of camshaft rotation; and a negative G-weight assembly comprising a negative G-weight movably mounted on said frame and bearing against the rate cam of said camshaft assembly for impeding the rotation of said camshaft assembly fromthe dead center commit to the terminal position and a spring biasing means biasing said negative G-weight toward said rate cam; said negative G-weight being movably activated from said rate cam against the resistance of said spring biasing means by the force of deceleration.

15. An inertial switch device for controlling the electrical circuits on a ballistic missile and operable in an acceleration-deceleration environment comprising: a frame, an electrical switch having exposed contact points mounted on said frame, a safety switch block having one end covered with a dielectric and having the opposite end pivotally joined to said frame in such spaced relationship to the contact points of said switch as will permit the dielectric covered end to pivotally enter between the open contact points of said switch, operating means joined to said frame, a coupling operably joining said switch block and said operating means, said operating means having an initial position for opening the contact points on said switch and pivotally moving the dielectric covered end of said switch block between the open contact points and a terminal position for pivotally retracting said switch block and closing the contact points of said switch, and operating means comprising a camshaft assembly journaled in said frame on antifriction bearings and a power spring cantileverly mounted to said frame and engaging said camshaft assembly; said camshaft assembly comprising an arming cam and a rate cam in angularly displaced relationship on a common axis of rotation, said power spring engaging'with the arming cam and motivating the rotation of said camshaft to the initial position on one side of the dead center commit position of engagement and to the terminal position on the other side of the dead center commit position of engagement with the arming cam, adjusting means joined to said frame for adjusting the initial position of said camshaft assembly, adjusting means joined to said frame for adjusting the terminal position of said camshaft assembly, a positive G-weight movably mounted to said frame on antifriction bearings and bearing at right angle against the arming cam for rotating said camshaft assembly from the initial position to at least slightly beyond the dead center commit position of engagement with said power spring, said positive G-weight being restrained against lateral movement by said antifriction bearings and being movably activated when the G-range of acceleration reaches a predetermined intensity, said operating means being nonintegrating to return to the initial position from any movement produced by a single pulse of said positive G-Weight not advancing said camshaft assembly to at least the intermediate dead center commit position, damping means coupled to said operating means for establishing a time base required for said camshaft assembly to move from the initial to the terminal position, said damping means being an untuned escapement directly coupled to one end of said camshaft assembly and operable in either direction of camshaft rotation, a negative G-Weight assembly comprising a negative G-weight movably mounted to said frame on antifriction bearings and bearing at right angle against the rate cam of said camshaft assembly for impeding the rotation of said camshaft assembly from the dead center commit to the terminal position and a spring biasing means biasing said negative G-Weight toward said rate cam; said negative G- weight being restrained against lateral movement by said antifriction bearings and being movably activated from said rate cam against the resistance of said spring biasing means by the force of deceleration, and adjusting means joined to said negative G-weight for controlling the re sistance offered by said spring biasing means to the movement of said negative G-weight by the force of deceleration.

16. An inertial switch device of the character claimed in claim 15 in which:

(a) the electrical switch is a multipole switch;

(b) the dielectric covered end of the safety switch terminates in a rake-like structure having a like number of blades as there are poles 0n the switch, each blade being covered by a dielectric material bonded 5 thereto;

(c) the coupling joins the safety switch block to the camshaft assembly of the operating means.

References Cited by the Examiner UNITED STATES PATENTS Iughes et al. 200-6l.52 Watanabe 340-l64 Taylor 20()l53 Teague et a1 73-514 Saunderson ZOO-61.45 Barifli 73-514 Weaver 20061.45 Weaver 73503 Smith 200--61.45 Schultz et al 200-61 KOci 200-15 BERNARD A. GILI-IEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner. 

1. A SWITCH DEVICE COMPRISING: A FRAME, A CAMSHAFT JOURNALED IN SAID FRAME, BIASING MEANS ENGAGING WITH AND BIASING THE ROTATION OF SAID CAMSHAFT TO AN INITIAL POSITION ON ONE SIDE OF THE DEAD CENTER POSITION OF ENGAGEMENT AND TO A TERMINAL POSITION ON THE OTHER SIDE OF THE DEAD CENTER POSITION OF ENGAGEMENT, MEANS ROTATING SAID CAMSHAFT FROM THE INITIAL POSITION TO AT LEAST SLIGHTLY BEYOND THE DEAD CENTER POSITION OF ENGAGEMENT WITH SAID BIASING MEANS, MEANS REGULATING THE RATE OF ROTATION OF SAID CAMSHAFT, MEANS IMPEDING SAID REGULATING MEANS TO INCREASE THE ELAPSED TIME REQUIRED FOR SAID CAMSHAFT TO ROTATE FROM THE DEAD CENTER TO THE TERMINAL POSITION, AND A SWITCH ACTUATABLE BY THE ROTATION OF SAID CAMSHAFT. 